Using computerized axial tomography scans of full chest and full chest fluoroscopic magnetic tape recordings, we will measure regional changes in lung volume, mass, and weighted mass. These studies are to determine the effects of trauma and operative injury on chest cage and diaphragmatic motion and gravitational force for fluid filtration and lung expansion. These studies are coordinated with clinical studies to determine optimum treatment of acute post-trauma respiratory insufficiency with the goal of developing decision logic to control therapy; in animals, to assess the effects of gravity and hemodilution on the Starling forces.